1. Field of the Invention
The present invention relates generally to a dispensing arrangement for partially solidified materials such as sherbets, soft ice creams and yogurts, and more particularly pertains to a dispenser of the aforementioned kind which delivers a precisely quantified portion of such materials on a controlled and repetitive basis.
2. Description of the Prior Art
Many types of apparatus are known in the prior art for dispensing partially solidified desserts such as sherbets soft ice creams, and yogurts. The dispensing arrangments normally have a dispensing nozzle, a valve associated therewith to control the dispensing operation, and a pump for feeding soft desserts to the nozzle. Manually controlled dispensing arrangements, wherein an operator controls operation of the dispensing valve, have some serious disadvantages associated therewith. The operator should maintain the dispensing valve open for a relatively constant time period over and over again in a repetitive manner, as the time the valve is open substantially determines the amount of dessert delivered for collection on top of cones, cups, wafers or the like. Moreover, a further disadvantage of this type of dispensing arrangment is that it often requires the presence of supervisory personnel to assist unskilled operators in the performance of their duties to prevent the delivery of either too little dessert, resulting in customer dissatisfaction, or too much dessert, resulting in an overdelivery for that purchase. This can be a relatively severe problem as the profits from this type of retail business are often related directly to the quantity of dessert dispensed on a repetitive basis.
An improvement over manually controlled dispensers is the provision of a timer controlled dispensing arrangement wherein the dispensing valve is maintained open for a given period of time determined by a timer. Simonich U.S. Pat. No. 3,399,809 discloses an ice cream vending machine having a mechanical timer therein such that a motor driven rotation of a mechanism results in a dispensing operation over a given fixed time period. Vollmer, Sr. U.S. Pat. No. 3,054,534 and Glisenti U.S. Pat. No. 3,456,839 disclose dispensing arrangements wherein an electrical timing circuit measures a given time period during which a soft dessert such as ice cream is dispensed. Unfortunately, these prior art dispensing arrangements do not offer a sufficient amount of flexibility to accommodate changes in important parameters which affect the dispensing operation, particularly those which influence the quantity of dessert dispensed during a given time period.